Science Fiction
Dictionary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
 |
XNAV Steer Your Way By X-Ray Pulsar
XNAV - or X-ray Navigation - could be the GPS of the solar system (or even the galaxy). X-ray astronomers have mapped a substantial number of x-ray pulsars whose pulsed emissions are as regular as atomic clocks. Several papers will be presented at the IEE/ION PLANS 2008 conference describing how this idea could be applied for spacecraft navigation.
An X-ray pulsar is a magnetized neutron star in a binary star system with a normal companion star. The strength of the magnetic field of a neutron star is a trillion times as large as the Earth's magnetic field strength measured on the Earth's surface.
(X-ray pulsarx-ray pulsar)
Material from the companion star is taken in by the neutron companion, directed into the magnetic poles. This gas falls into the neutron star at speeds of up to half the speed of light; the resulting hotspots generate temperatures of more than a million degrees. As the neutron star rotates, these polar hotspots produce regular pulses of x-ray radiation like lighthouses.
These sources are highly reliable, and are fixed in position. Phase measurements of these sources can be used to establish the location of a spacecraft.
Several different improvements to the use of X-ray Navigation have been proposed. In Noise Analysis for X-ray Navigation Systems, it is suggested that the performance of an XNAV system beyond the orbit of Jupiter could be accurately predicted.
In Online Time Delay Estimation of Pulsar Signals for Relative Navigation using Adaptive Filters it is suggested that the positions of two spacecraft could be determined if both are locked to a known pulsar which emits a waveform that reaches them with a differential time delay that is proportional to the distance between the spacecrafts. The spacecrafts' relative inertial position could be determined by observing appropriately distributed pulsar sources.
Astronomers have thought long thought about pulsars, which were discovered in 1967, as some kind of interstellar beacon. The incredible regularity - and rapidity - of the signal pulsation seemed (at that time) to have no natural explanation.
However, science fiction writers thought about it at least fifteen years earlier. And what's more, suggested that it might be possible to create beacons. In his 1952 story Troubled Star, George O. Smith wrote about space beacons which were created to ease galactic space travel:
"We use the three-day variable to denote the galactic travel lanes. Very effective. We use the longer variable types for other things - dangerous places like cloud-drifts, or a dead sun that might be as deadly to a spacecraft as a shoal is to a seagoing vessel. It's all very logical.""...you're going to make a variable star out of Sol, just for this?"
Scyth Radnor shook his head. "Please do not think us hard... You're not going to insist that your animal comforts are more important than the functioning of a galaxy-wide civilization?"
(Read more about space beacons)
From IEE/ION PLANS 2008 via io9.
Scroll down for more stories in the same category. (Story submitted 5/8/2008)
Follow this kind of news @Technovelgy.| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |
Would
you like to contribute a story tip?
It's easy:
Get the URL of the story, and the related sf author, and add
it here.
Comment/Join discussion ( 1 )
Related News Stories - (" Space Tech ")
SpaceX Wants A Moonbase Alpha
'And he had been sent with troops, supplies and bombs to command Russia's most trusted post, the Moonbase.' - L. Ron Hubbard, 1948.
NASA Wants Self-Driving Or Remote-Controlled Vehicles For Lunar Astronauts
'THE autobus turned silently down the wide street of Hydropole. Robot-guided, insulated from noise and cold...'
Orbital Mechanics, The Liftoff, The Turnover, The Retrograde Burn
'...the huge vessel had spun, with a sickening lurch, through a complete half-circle, the instant the power was reversed.' - EE 'Doc' Smith, 1928.
Can A Human Land A SpaceX Rocket On Its Tail?
'If she starts to roll sideways — blooey! The underjets only hold you up when they’re pointing down, you know.' - Stanley G. Weinbaum, 1936.
Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.
Science Fiction
Timeline
1600-1899
1900-1939
1940's 1950's
1960's 1970's
1980's 1990's
2000's 2010's
Current News
Brin's 1990 Novel Earth Still Full Of Predictions
'... making the point that their likenesses, every move they made, were being transmitted.'
'Whisper Mode' ala Blue Thunder Researched At Bristol
'Forest Lawn.'
Gaia - Why Stop With Just The Earth?
'But the stars are only atoms in larger space, and in that larger space the star-atoms could combine to form living matter, thinking matter, couldn't they?'
Microsoft VASA-1 Creates Personal Video From A Photo
'...to build up a video picture would require, say, ten million decisions every second. Mike, you're so fast I can't even think about it. But you aren't that fast.'
Splendid View Of Eclipse From Orbit Visualized And Repurposed By Arthur C. Clarke
'The area affected was five hundred kilometres across, and perfectly circular.'
Bespoke Environment Music From AIs
'Call 'em Winter Mute," said the other, making it two words.'
Goldene - A Two-Dimensional Sheet Of Gold One Atom Thick
'Hasan always pitched a Gauzy - a one-molecule-layer tent, opaque, feather-light, and very tough.'
SpaceX Wants A Moonbase Alpha
'And he had been sent with troops, supplies and bombs to command Russia's most trusted post, the Moonbase.'
Vast Apartment Living Will Get Even More Vast
'What is your population', I asked. 'About eighty millions.'
NASA Wants Self-Driving Or Remote-Controlled Vehicles For Lunar Astronauts
'THE autobus turned silently down the wide street of Hydropole. Robot-guided, insulated from noise and cold...'
Elon Musk Says Robotaxis Will Be Ready This August, 2024
'The car had no steering wheel, and no one drove!'
Moonwalkers AI-Controlled Electric Shoes
Now that's power walking that Hugo Gernsback would have approved.
Steve Jobs: 'Capture The Next Aristotle - With AI'
'It was disturbing to think of the Flatline as a construct...'
No Tips! Robotic Food Delivery In Phoenix
'...he rewired the delivery robot so that it would serve him midnight snacks.'
Electric Catamaran 'Explorer Eco 40m' Has 'Solar Skin'
'On went the electric-yacht faster and still faster.'
Orbital Mechanics, The Liftoff, The Turnover, The Retrograde Burn
'...the huge vessel had spun, with a sickening lurch, through a complete half-circle, the instant the power was reversed.'
